I haven't a clue as to the value of your paper model. I am a Howard Hughes historian/lecturer. I used to have a similar scale model of the Hughes H-1 Racer, XF-11, Locheed L-14 and the Spruce Goose. They were severely damaged by rain so I tossed them.
Just give me a ball park price for the H-1. FYI: There is some current activity about the XF-11. Fans fight for Lee museum -- Page 2 -- Times Union - Albany NY:1492:
The heirs of Sgt. Bill Durkin who pulled Hughes from the burning wreckage is currently to be auctioned on September 17th.